Obesity is a global epidemic that greatly increases chronic disease burden. Overeating of highly palatable (HP) foods, especially in the ubiquitous food cue environment and in the context of stressful life events, are known to promote HP food craving, intake and weight gain, but the differential biobehavioral mechanisms underlying these effects is unclear. Using a novel experimental paradigm, promising preliminary results indicated that brief exposure to food cue and to emotional stress increases motivation for and intake of HP snack foods in the laboratory, more so in overweight (OW/OB) than in lean (LN) individuals. Furthermore, OW/OB individuals show altered biological stress and metabolic states with different biobehavioral responses during food cue and stress exposures which predict HP food craving and intake. On the basis of these results, we propose a 5-year experimental study with a prospective 2-year longitudinal follow-up in healthy men and women categorized on the basis of lean (body mass index: BMI<25), overweight (BMI=25-29.9) and obese Class I (BMI=30-35) groups to test the hypothesis that food cue and stress will increase HP food craving and intake, and higher BMI-related metabolic and stress system adaptations will predict HP food motivation and intake, which in turn, will promote future weight gain and obesity. The specific aims are: (1) to examine if exposure to food cue and to stress vs. neutral relaxing cues differentially increase HP food craving, eating topography, emotion, hunger and alters physiological and biochemical responses, and if changes vary across BMI groups; (2) to assess differential increases in HP food intake in each condition and whether it varies as a function of BMI group; (3) to identify whether HP food craving, emotion, hunger, physiological and metabolic responses is predictive of eating topography measures, calories and weight of HP food intake in each condition; (4) to assess whether stress- and food cue-induced HP food craving, intake and laboratory responses are predictive of food motivation, dietary intake and weight gain over the 2-year follow-up period; and (5) to explore the influence of key individual differences variables of cumulative stress, eating patterns, and physical activity on stress and cue-related responses and food intake in the laboratory and on motivation for HP food intake in the two-year follow-up period. Successful completion of the project will lead to an innovative and valid method to model of HP food craving and intake in the laboratory, which may be utilized for testing novel intervention strategies to decrease high levels of food motivation, overeating and obesity risk.